Animal Models

jabudny at EARTHLINK.NET ("John A. Budny") wrote:
>Should a criteria for an animal model for toxicology be that the time-course
>and characteristics of the toxicologically-induced
>disease state resemble, replicate or be identical to the toxicant-induced
>disease condition in humans?
Clearly we have to distinguish between toxicant induced disease and
vector induced disease. Many diseases are species specific, cf your
comment re tuberculosis, and pharmacologists have different models,
often isolated tissues, to study efficacy and pharmacodynamics.
In many cases of toxicant induced damage, it will be defined in
animals, but the human response may never be known (regulatory
toxicology). The search for an animal model to mimick human toxicity
arises when adverse effects are noted in humans; then the interesting
part starts. I guess if you ask a pulmonary toxicologist if he would
like an 'identical' animal model for cigarette smoke induced lung
neoplasia that is cheap and easily housed, he would be very happy.
In the pragmatic world, I think we have to accept a 'resemblance' so
that at least a start can be made on evaluating toxic mechanisms, then
accept that in some cases different models, including some unusual
ones, will have to be used to evaluate different aspects of toxicity
(eg organophosphorus neurotoxicity in chickens). One identical model
for the spectrum of human toxicity would be ideal, but often several
models for different aspects resembling human toxicity is all we can
hope for.
Paul Whitehead BSc CBiol MIBiol DABT
United Kingdom
e-mail p.whitehead at dial.pipex.com